THACKERSVILLE, Okla. (AP) — At least 14 people have been injured and transported to hospitals after trusses holding up the entrance to a resort where the Backstreet Boys were set to begin a concert in Oklahoma collapsed.

WinStar World Casino and Resort says in a statement posted on Twitter Saturday that the resort began an evacuation at about 5 p.m. when lightning was within four miles of the casino.

The company says about 150 patrons did not evacuate and when the storm hit with 70 to 80 mph winds, it knocked over trusses and the entrance collapsed on them. Of the 14 people taken to a hospital, two have been released.

Band member Kevin Richardson tweeted that the concert had been sold out with about 12,000 fans.